Food package for amines control or removal

Abstract

A food package suitable for manufacturing as a closed packaging system contains an amine-absorbent element comprising ammonium-exchanged mordenite (MOR) type zeolites and optionally further comprises ZnO-doped Faujasite (FAU) type zeolites and/or CuO-doped ZSM-5 type zeolites.

Claims

1. A food package manufactured as a closed packaging system and having an internal volume and a head space, for amines odor control or removal, said food package comprising an amines-releasing food and containing an amine-absorbent element comprising ammonium-exchanged mordenite type zeolites with a Si/Al atomic ratio between 5 and 20, wherein said ammonium-exchanged mordenite type zeolites are present in an amount between 2 μg and 50 μg is per gram of weight of the amines-releasing food; and the ammonium-exchanged mordenite type zeolites are in the form of powders with X.sub.90 between 0.2 and 10 μm.

2. The food package according to claim 1, wherein said Si/Al atomic ratio is between 8 and 20.

3. The food package according to claim 1, wherein the amine-absorbent element further comprises ZnO-doped Faujasite type zeolites with a Si/AI atomic ratio between 2 and 30.

4. The food package according to claim 3, wherein said ZnO-doped Faujasite type zeolites are present in an amount between lug and 40 μg per gram of weight of the amines-releasing food.

5. The food package according to claim 1, wherein the amine-absorbent element further comprises CuO-doped ZSM-5 type zeolites with a Si/Al atomic ratio between 10 and 50.

6. The food package according to claim 5, wherein said CuO-doped ZSM-5 zeolites are present in an amount between 1.5 μg and 40 μg per gram of weight of the amines-releasing food.

7. The food package according to claim 1, wherein said powders are contained in a bag.

8. The food package according to claim 1, wherein the hag is composed of a material selected from the group consisting of low density polyethylene (LDPE), high density polyethylene (HDPE), polypropylene (PP), ethylene-vinyl acetate (EVA), polystyrene (PS), styrene-ethylene-butylene-styrene (SEBS), polylactic acid. (PLA), polyesters, and biopolyesters.

9. The food package according to claim 8, wherein the bag is placed in the internal volume of the food package.

10. The food package according to claim 9, wherein the bag is placed in the head space of the food package.

Description

EXAMPLE

(1) MOR (NH4) is selected as sample S1, according to the present invention, and has an average size comprised between 2 μm and 10 μm and a Si/Al ratio of 10 as summarized in Table 1.

(2) Similarly, samples S2-S5 have been prepared by mixing MOR zeolites with FAU and ZSM-5 ion-exchanged zeolites as reported in Table 1.

(3) Comparative sample 1 (C1) MOR (H) zeolites are prepared by thermal treatment at 500° C. for 5 hours in air, from the same samples identical to the above S1. This thermal treatment allows to remove ammonium ions from the zeolite framework resulting in un-exchanged MOR (H) zeolites having an average size comprised between 2 μm and 10 μm and a Si/Al ratio of 10.

(4) Comparative sample 2 (C2) ZnO-doped MOR (H) zeolites were prepared, first, by thermal treatment, at 500° C. for 5 hours in air, of the sample MOR (NH4) and then, by ion exchange process. MOR (H) zeolites have an X.sub.90 comprised between 0.2 μm and 10 μm. 10 g of zeolites were dispersed in a solution of zinc salt (e.g. nitrate salt or acetate salt) then filtered on a filter paper and thermally treated to promote the solvent evaporation.

(5) Resulting zinc-exchanged amount is about 2.4% wt over MOR zeolites weight, as evaluated by ICP Mass Spectrometry.

(6) TABLE-US-00001 TABLE 1 Samples description 1.sup.st zeolite 1.sup.st zeolite 2.sup.nd zeolite 2.sup.nd zeolite 1.sup.st/2.sup.nd Sample Si/Al cation 2.sup.nd Si/Al cation zeolite ID 1.sup.st zeolite atomic ratio exchanged zeolite atomic ratio exchanged ratio S1 MOR (NH4) ~10 NH4 — — — — C1 MOR (H) ~10 H+ — — — — C2 MOR (H) ~10 Zn — — — — S2 MOR 10 NH4 FAU 15 Zn 1 S3 MOR 10 NH4 ZSM5 11.5 Cu 1 S4 MOR 10 NH4 FAU 15 Zn 0.43 S5 MOR 10 NH4 ZSM5 11.5 Cu 0.43

(7) Zeolites reported in Table 1 are tested under Temperature Program Desorption (TPD) technique to determine the kinetic and thermodynamic parameters of desorption process. Each sample is heated with a temperature program and the partial pressures of atoms and molecules evolving from the sample are detected.

(8) The reactor is saturated under static conditions by injecting 10 cm.sup.3 of gaseous TMA left for 10 min at 30° C. After saturation, the reactor is connected on-line with the carrier flow, recording the release of TMA at the saturation temperature (dead volume). TPD is finally carried out up to 500° C.

(9) The results are reported in the following table 2 in order to provide an overall picture for the tested zeolites. The zeolite characteristics and the correlation between results and zeolites characteristics are discussed below.

(10) TABLE-US-00002 TABLE 2 Sample results desorbed TMA TMA sorption capacity Sample (mmol/g.sub.zeo) (% wt) S1 1.33 7.86 C1 0.78 4.61 C2 0.67 3.96 S2 1.05 6.20 S3 1.02 6.00 S4 1.25 7.40 S5 1.32 7.78

(11) Considering the characterization results, all MOR zeolites exhibit larger acid sites (i.e. higher overall amine sorption amount) than other commercially available zeolites but sample S1 with ammonium-exchanged MOR zeolites ensures a higher amount of sorbed TMA if compared to comparative sample C1 with un-exchanged MOR. Sample C2, i.e. zinc oxide doped MOR zeolites, confirmed a lower overall TMA sorption capacity.

(12) Furthermore, Samples S2-S5 have been prepared as mixture of MOR zeolites with FAU and ZSM-5 ion-exchanged zeolites, with the aim of proving the maintenance of high levels of TMA absorption, while improving the possible package applications. In fact, the addition of ZnO-doped Faujasite (FAU) type zeolites increases the sorption capacity of the system while keeping high reversibility at temperature lower than 100° C., or the use of CuO-doped ZSM-5 type zeolites, improves the sorption capacity in the range comprised between 150-270° C.).